Micro-CT for SEM
Non-destructive Measurement and Volume Visualization of Specimens’ Internal Microstructure in SEM
Micro-CT
Innovation with Integrity
3D Microscopy Using Micro-CT for SEM
Micro-CT for SEM adds true 3D microscopy to your SEM – regardless of manufacturer and model.
Micro-CT for SEM extends the surface information gained with conventional SEM imaging by allowing an unique insight into the specimen’s internal microstructures –non- destructively and with ease of use.
Obtain information on a specimen’s internal microstructure non-destructively and without any additional sample preparation
Measure and visualize the internal morphology in 2D and 3D
Generate realistic models for a virtual travel through a specimen
Intuitive and easy-to-use software for 3D rendering, visualization as three orthogonal sections or as slice-by-slice movie
Scanning volume is up to 4 mm in diameter, maximum sample length is 10 mm
Details are detectable down to a size of 400 nm
Precision rotation stage for high resolution images
Direct detection X-ray cameras with 512 x 512 or 1024 x 1024 pixels
Installable on any SEM with a free port of at least 65 mm in diameter Micro-CT for SEM at a Glancecorresponds to the complete internal 3D struc- ture of the object obtained non-destructively.
It can be displayed as virtual slices in any orientation or as a realistic three-dimensional visual model, which includes not only surface information (as in conventional SEM imaging), but also all internal object details.
True 3D microscopy
Micro computed tomography or “Micro-CT”
is X-ray imaging in 3D, by the same method used in hospital CT (or “CAT”) scanners, but on a small scale with massively increased resolution. It really represents 3D microscopy, where the fine internal structure of objects is imaged non-destructively. The Micro-CT system will add a unique possibility to image and measure 2D/3D morphometry throughout the entire sample volume to your SEM, and to create realistic visual models for virtual travel within the object.
Working principle
An electron beam in the SEM column hits a metal target and produces X-rays. This radia- tion is acquired by a sensitive X-ray camera mounted on a flange on the side of the SEM specimen chamber. An object is positioned on the precision rotation stage between the target and camera within the X-ray beam. During scanning, a computer controls the object rota- tion and acquires a number of angular shadow projections of the objects’ internal microstruc- ture from the X-ray camera.
A special program back-projects all acquired shadow images of the object’s internal micro- structure in the computer memory. The com- bined information from all angular projections
Analysis with Micro-CT
Left – The standard SEM image in SE mode displays the 3D surface of the object as a two- dimensional flat picture.
Object: plastic foam.
Right – The Micro-CT for SEM allows visualization and measurement of the true 3D internal microstructure of the object without any physical cut or additional preparation.
Standard SEM image and Micro-CT visualization
Generation of internal microstructures
Top – Measurement configuration on a SEM; Bottom – back-projection of an object‘s internal microstructure
Computer Memory
Object
X-ray camera
SEM
Microscanner and X-ray camera
The Micro-CT system can be installed in any new SEM or retrofitted to old instruments. It works with any PC which has two USB 2.0 ports. A PC or laptop can be supplied option- ally with preinstalled software.
The Micro-CT system
The Micro-CT system for SEM contains several modules to add a 3D imaging modality to any SEM without compromising standard imaging modes. The Micro-CT system does not require any changes to the standard SEM construction.
A microscanner contains the target to produce X-rays, an object rotation stage, and a moto- rized linear stage to vary the distance between the X-ray emission point and the object for adjusting the magnification of the X-ray images. The microscanner can be installed inside the specimen chamber in place of stan- dard object holders.
A camera assembly is attached to the flange in the side wall of the specimen chamber. It con- tains an X-ray camera, a vacuum feed through for connection to the microscanner and a shutter with an alignment pattern. The camera assembly is connected to the microscanner controller, which takes power and receives commands from a USB port and controls all movement of the microscanner parts. The X-ray camera is also connected to the com- puter through a USB interface.
Micro-CT for any new or old SEM
A Wide Field of Application
Composite materials
Electronics
Heat shielding ceramic
Glass fiber/epoxy composite material containing 10–12 micron fibers in an epoxy matrix. From left to right: 1) SEM image in SE mode; 2) X-ray image through this sample, acquired using the Micro-CT for SEM; 3) a virtual section, obtained non-destructively by Micro-CT for SEM; 4) a 3D model of the internal microstructure built from all reconstructed cross sections with a virtual cut on an inclined plane; all X-ray images have a pixel size of 705 nm.
Top left – SEM image in SE mode Top right – X-ray shadow image
Bottom left – a virtual slice (notice that true internal porosity is much bigger than seen on the SEM image) Bottom right – 2D and 3D analysis of the internal porous space
Several X-ray images through a small surface-mounted light emitting diode (LED) with a plastic lens and insulating body. The Micro-CT system for SEM includes a special cap to protect non-conductive objects from electron charge for imaging and slicing without any coating.
Filter inspection
Used filter from a vacuum cleaner filled with dust particles. From left to right: 1) SEM image of the filter surface in SE mode. The other three images show the results of Micro-CT reconstruction where the filter material is shown in silver, and dense particles in red; 2) front view; 3) back view; 4) side view with semitransparent filter material; notice that most particles are absorbed within the front surface of the filter (figures 2 and 4) and cannot pass through the filter material.
Wood and plants
Top – SEM image of wood sample in SE mode Right – orthogonal virtual slices through a 3D reconstructed internal microstructure obtained non-destructively using the Micro-CT for SEM.
Left – SEM image of paper sample in SE mode
Right – 3D model based on results obtained by the Micro-CT for SEM with a virtual cut by a plane in the top front of the sample.
Paper
Dragonfly
Clasper-organs at the tip of the abdomen of an Ischnura elegans sample prepared with critical point drying, analyzed using a SEM with Schottky FE source. Top – X-ray projection image of the abdomen;
Middle – Coronal virtual slice;
Bottom – Volume rendered 3D model of the dragonfly created from reconstructed slices.
Easy-to-Use Software
The Micro-CT for SEM is supplied with a software package for Windows 7, Vista or XP, which includes a control program, 3D recon- struction, morphological analysis and realistic visualization tools.
Using a simple intuitive user interface, the control program for the Micro-CT for SEM acquires images from the X-ray camera, adjusts magnification and angular position of the object for X-ray imaging, collects a set of angular shadow projections through the object for 3D reconstruction and supports calibration of the camera and microscanner.
Volumetric reconstruction “NRecon” converts acquired angular projections into slices through the object. It provides misalignment correction, ring artifact suppression, volume of interest selection, reconstruction of objects larger than the field of view and density window adjustment.
The reconstructed set of slices can be flexibly viewed in the “Data Viewer” program. Images are displayed as a slice-by-slice movie or as three orthogonal sections, centered at any point inside the reconstructed space. You can add smoothing, save sagittal or coronal slices, measure distances and intensity profiles, turn the reconstructed object in any direction and save as alternatively oriented dataset.
“CTanalyser” analyzes results for morpho- metry and densitometry. The software fea- tures include:
Loading datasets as .tif, .bmp and .jpg;angular resampling
Advanced volume of interest (VOI) selection tool
2D/3D distances and angles measurements
Image processing: e.g. smoothing and despeckling
Morphological measurements in 2D and 3D, such as sizes, areas, perimeters, volumes, shapes, orientations, moments of inertia
Automated batch analysis, adding user plug-ins“CTvol” (surface rendering) and “CTvox”
(volume rendering) provide virtual 3D view- ing environment, flexible and rich in features, to give you a wide range of options for 3D presentation of Micro-CT results.
Movement and rotation of the object model(s)
Selection of background including scenery
Selection of viewing angle, light direction and color
Control of object texture, color, transparency
Cut models along a selected plane
Semi-automated creation of animated“movies”
Software components
Simple intuitive user interface
CTanalyser
CTvol
NRecon
Data Viewer
The software package includes an acquisition program, a 3D reconstruction module, a viewing program, a powerful package for 2D and 3D numerical analysis of object’s internal morphology and a program for 3D rendering with realistic visualization and movie creation.
All configurations and specifications are subject to change without notice. Order No. DOC-B76-EXS001, Rev. 1.3. © 2015 Bruker Nano GmbH. Printed in Germany.
Technical Specifications
Nominal resolution 400 nm – 8 µm pixel size (depends on magnification) Low-contrast resolution typically 800 nm
Object size 0.18 – 4 mm scanning diameter, 10 mm maximum object length Object manipulator precision rotation 0.45 deg min. step size; motorized zoom
with feedback
Manipulator controller microprocessor controller powered (with manipulator) from USB 2.0
X-ray camera direct detection cooled CCD, 512 x 512 pixels or 1024 x 1024 pixels, 16-bit
Integration time typical exposure time: 2 – 4 s, possible range: 0.5 to >100 s Required space on flange 65 mm in diameter on any flange of the SEM specimen chamber Camera power supply 100 – 240 V AC, 47– 63 Hz, 1.9 A max. (power supply included) X-ray target material standard: Brass (8 – 9.6 keV), fixation for user-selected targets Required e-beam current typically more than 100 nA
Connections to PC two USB 2.0 ports (two 5 m cables included); PC not included Environmental conditions 15 – 30 °C (5 – 45 °C storage), < 85 % humidity, no condensation
The Micro-CT system includes the following standard parts:
Microscanner for object manipulation within the vacuum of the SEM specimen chamber, with precision rotation stage and motorized zoom adjustment with sensor to measure magnification
Camera assembly including X-ray CCD camera with Beryllium front window, connection flange with vacuum feed through for electrical connections to microscanner, alignment target, shutter, flanges and all necessary sealing components for mounting on the SEM specimen chamber
Power supply unit for X-ray CCD camera with power cables
Microprocessor controller for microscanner manipulation from computer through USB 2.0 port
Two targets for microscanner to emit X-rays: short arm for high magnification imaging and long arm for scanning large objects
Special cap with X-ray windows for imaging and scanning non-conductive objects without coating
Two specimen stages, which allows mounting of a new sample whilst scanning the current one
CD with control, reconstruction, analysis and visualization programs, all necessary drivers and electronic version of documentation and manuals
Bruker Nano GmbH Berlin · Germany
Phone +49 (30) 670990-0 Fax +49 (30) 670990-30 [email protected]
www.bruker.com/micro-ct-for-sem
